Below are a few photos that I don’t think have been posted here before, along with some key ones that have been. Keep your eye on the smaller palm tree on the left.

No location is given, just “California Fan Palm” and “c. 1886.” But given the subsequent photographic evidence, this is a pre-1886 view of the Hammel Palms, perhaps with a special guest appearance by Mrs. Hammel:
CA State Library -- http://catalog.library.ca.gov/exlibr...24IANV93FA.jpg

Same three trees in relation to each other (two that appear almost as one, and a shorter one to the left), same well, same fence behind the trees:
USC Digital Library – http://digitallibrary.usc.edu/cdm/si...d/13965/rec/62 (reversed there, correct here)
USC caption is: "The two [sic] old palms on San Pedro Street, home of Sheriff Hummel [sic], showing old well, ca. 1885.”
[Remember, Dr. William A. Hammel came to L.A. in 1856 and died in 1889. His son, William A. Hammel, was born in 1865 and became L.A. County Sheriff in 1899.]

Let’s back up to the street and look west. Those same three trees (two that appear almost as one, and a shorter one to the left) can be seen between the middle two trees along the brick wall. The arrow points to the same brick house as in the photo above. That brick house may have been the Hammel home, or it may have belonged to the adjacent property owner, in which case the Hammels may have lived in the building on San Pedro Street (the advertising on that building in this photo is not evident in other photos):
USC Digital Library -- http://digitallibrary.usc.edu/cdm/si...d/13914/rec/11 (reversed there, correct here)
USC caption is: "The old palms of San Pedro Street under Second. Home of Sheriff Hammel, Los Angeles. c. 1886-87."

Looking east at the same trees from the other side of the brick wall. Now the same two palms that almost appear as one are on our left, and the smaller palm of the three is on our right with a ladder leaning against it. I believe this and the following four photos (three + a closeup) document the transplanting of one of the Hammel palms to Arcade Depot:
LAPL -- http://jpg3.lapl.org/pics37/00068408.jpg
LAPL caption is: "The moving of palms on the east side of San Pedro Street, between 2nd and 3rd Street, on the old Wallace Woodworth property. A crew of men is working on the project, using a tall ladder and a horse and wagon. An orchard lies behind a wall. Photo dated: 1888." [No, it's the William Hammel property on the west side of San Pedro Street. We've been over that before.]

Looking west again. At the right edge of the photo is the same brick house we’ve seen before, then the two palms that almost appear as one, then the shorter one to the left, which is now in a crate. Look at the old guy with the beard down in the hole next to the tree. Also, note the handwritten info in the corner of the photo:
LAPL -- http://jpg1.lapl.org/pics26/00032697.jpg
LAPL caption is: “Planting full-grown palm trees on San Pedro Street, between 2nd and 3rd streets in 1888.” [Not planting, digging up]

They’ve almost made it to the Arcade Depot. In front of the train station is a flat-roofed building advertising lager beer and which is casting a shadow into the open area between it and the station, which the pitched roof is a part of:
Huntington Digital Library -- http://cdm16003.contentdm.oclc.org/c.../id/3293/rec/2

Take a closer look at the old guy with the beard standing to the right of the crate . . . is it the same man who was down in the hole next to the tree? The crate appears to be the same, too. Looks like they had fun moving the tree, huh?

It’s got to be the same palm tree in all those photos . . . the smaller one on the left by the well on the Hammel property, then dug up and moved to the Arcade Depot in 1888.

After being moved from the Arcade Depot, for a number of years the tree is very hard to spot in photos. There aren’t any street-level photos readily available; only aerial views of Exposition Park and the construction of the Coliseum, which was completed in 1923. And unless the background is just right, a slender palm tree isn't all that easy to spot from far away. But I think the tree is there.

Closeup of the same photo showing Figueroa Street and 39th Street, and something in its own island on the west side of Figueroa:

I think you can also barely make it out here. Just to the left of the red arrow, a very thin line crosses Figueroa, topped by something darker than the empty lot to the east:
LAPL -- http://jpg2.lapl.org/pics39/00054254.jpg